Interviewing at Google Articles

brainteasers

you are at a party with a friend and 10 people are present including you and the friend. your friend makes you a wager that for every person you find that has the same birthday as you, you get $1; for every person he finds that does not have the same birthday as you, he gets $2. would you accept the wager?

You have 3 jars. Each jar has a label on it: white, black, or white&black. You have 3 sets of marbles: white, black, and white&black. One set is stored in one jar. The labels on the jars are guaranteed to be incorrect (i.e. white will not contain white). Which jar would you choose from to give you the best chances of identifying the which set of marbles in is in which jar.

Explain the Internet to your grandparents

Explain a database to a young child.

What is your favorite web site? Why? Now improve it.

Steve Jobs calls and asks you to improve the iPod. Go.

Youre in a boat with a rock, on a fresh-water lake. You throw the rock into the lake. With respect to the land, what happens to the level of the water in the lake goes up, goes down, stays the same?

I was asked to develop a marketing plan for packaged ice to native Alaskans.

It’s like this. Sanitary manhole covers are usually round (and solid, i.e. VERY heavy) but Storm sewer manhole and Inlet covers are usually square or rectangular grates which let water in. The deciding factor is where they are placed relative to the curb line. All covers are actually installed on a concrete generic ‘Mexican Hat’ structure which can be centered or offset to one side. The structure fits on the round concrete casting (5’ – 8” diameter) and can be made to accept any solid or grated casting. If this part of the world, where river flooding is fairly common, Sanitary manholes and lift stations are either raised above potential flood limits if possible or sealed and bolted shut, making them much more difficult to open. It’s also a very good idea to vent Sanitary manholes and lift station with a portable fan to avoid being overcome by methane and other gasses trapped in them.”

Pete Abilla was a little luckier and knew how to answer this question:You are at a party with a friend and 10 people are present including you and the friend. Your friend makes you a wager that for every person you find that has the same birthday as you, you get $1; for every person he finds that does not have the same birthday as you, he gets $2. Would you accept the wager?”

“The answer has to do with the number of days in the year and the probability the person’s birthday falls on the same day as mine (without replacement). I eventually solved it, but it took time learning how to apply probability with no replacement.”

Given a triangle ABC, how would you use only a compass and straight edge to find a point P such that triangles ABP, ACP, and BCP have equal perimeters? (Assume that ABC is constructed so that a solution does exist.)

When I come back, I want you to explain to me something complicated that I don’t already know.”

“How would you deal with changes being made a week or so before the ship date?

How would you deal with a bug that no one wants to fix? Both the SDE and his lead have said they won’t fix it.

Write a function that counts the number of primes in the range [1-N]. Write the test cases for this function.

Write the test cases for a vending machine.

Those were the questions I was asked. I had a lot of discussions about how to handle situations. Such as a tester is focused on one part of an SDK. During triage it was determined that that portion of the SDK was not on the critical path, and the tester was needed elsewhere. But the tester continued to test that portion because it is his baby. How would you get him to stop testing that portion and work on what needs to be worked on?

In my first Google phone interview I was asked how I’d verify that a random number generator was truly random

Why do you think you would do well at this job?

What is your greatest strength?

Explain how you would be an asset to this organization

Tell me about a conflict you have had with a coworker and how it was resolved.”